External or male threads of pipe must be protected against damage during movement such as by dragging of the pipe during handling and positioning in and about derrick areas in the course of drilling oil and gas wells. For example, pipe is typically stored in a ground level racking area adjacent the derrick. Prior to being transported to the derrick floor, shipping protectors are removed from threads of the pipe to permit thorough cleaning of the pipe and coupling followed by application of fresh thread compound. Then the coupling end of the pipe is hoisted into a vertical position in the derrick while the pin end of the pipe is dragged along a rack walkway and inclined ramp leading to the derrick floor. Unless the threads on the casing end, particularly the male end of the casing, are protected, they may be severly damaged thereby requiring reconditioning and, in any event, a slowdown of operations by having to remove the pipe from the drilling area and repeat the process. Thus, thread protectors are used to protect the threads of the pipe while being transported to the derrick floor, and these protectors must be quickly attached and detached from the pipe yet not be knocked off during movement of the pipe. In addition, the protectors must be capable of being reused repeatedly.
Many forms of thread protectors have been employed including devices that are forced-fitted to the ends of the pipe or other tubular members, devices that are attached to the pipe ends by means of mechanical linkages and devices that are attached to the pipe ends of means of pneumatic expansion of resilient members. The present invention is directed to an improvement in the latter type of protector device and a method of manufacture thereof.